Polymeric networks are used in a wide variety of fields in the art. In particular in recent years polymeric networks have attracted much attention which show inducible changes of the shape (shape-memory-properties), namely the so-called shapely-memory-polymers (SMP). Such SMP-materials are, for example, described in the applications WO99/42528 and WO99/42147. In view of the reversible change of shape, these materials are of high interest in a wide variety of fields, in which, for example, a change of the size is desired. This is, for example, true for medicinal implants, which desirably should only reach their final size after having reached the final destination, so that the introduction of these implants requires only minimal invasive chirurgical practices.
Although SMP-materials are already known in the prior art, these materials do show several drawbacks. A lot of SMP-materials, for example, lose their shape-memory-properties if the reversible change of shape is induced several times in several cycles. Furthermore, a lot of SMP-materials do not show the desired compatibility with tissue, required for the application in the medicinal field. Even the sometimes desired property of being biological degradable, for example, desired for some applications in the medical field, is sometimes not achievable. Furthermore, the know biodegradable SMP-materials do often show the undesired property, that the mechanical properties of the material change rapidly after having reached a certain threshold, although the degradation is not yet complete. A typical embodiment of this drawback is a strong embrittlement, which may cause problems in particular in the medical field, for example, when these materials are used as implants. Furthermore, a lot of the known SMP-materials are hard to modify with respect to desired thermal and mechanical properties.
It is therefore the object of the present invention to provide a SMP-material which overcomes the drawbacks of the SMP-materials known.
This object is solved with the polymeric network in accordance with claim 1. Preferred embodiments are defined in the sub-claims.
Furthermore, the present invention provides an intermediate product, suitable for the preparation of the polymeric network in accordance with the present invention. Finally, the present invention provides methods for the manufacture of the polymeric network and for the intermediate product. Preferred embodiments are again defined in the sub-claims.